Liver specification of human iPSC-derived endothelial cells transplanted into mouse liver.

Background & Aims: Liver sinusoidal endothelial cells (LSECs) are important in liver development, regeneration, and pathophysiology, but the differentiation process underlying their tissue-specific phenotype is poorly understood and difficult to study because primary human cells are scarce. The aim of this study was to use human induced pluripotent stem cell (hiPSC)-derived LSEC-like cells to investigate the differentiation process of LSECs. Methods: hiPSC-derived endothelial cells (iECs) were transplanted into the livers of Fah-/-/Rag2-/-/Il2rg-/- mice and assessed over a 12-week period. Lineage tracing, immunofluorescence, flow cytometry, plasma human factor VIII measurement, and bulk and single cell transcriptomic analysis were used to assess the molecular and functional changes that occurred following transplantation. Results: Progressive and long-term repopulation of the liver vasculature occurred as iECs expanded along the sinusoids between hepatocytes and increasingly produced human factor VIII, indicating differentiation into LSEC-like cells. To chart the developmental profile associated with LSEC specification, the bulk transcriptomes of transplanted cells between 1 and 12 weeks after transplantation were compared against primary human adult LSECs. This demonstrated a chronological increase in LSEC markers, LSEC differentiation pathways, and zonation. Bulk transcriptome analysis suggested that the transcription factors NOTCH1, GATA4, and FOS have a central role in LSEC specification, interacting with a network of 27 transcription factors. Novel markers associated with this process included EMCN and CLEC14A. Additionally, single cell transcriptomic analysis demonstrated that transplanted iECs at 4 weeks contained zonal subpopulations with a region-specific phenotype. Conclusions: Collectively, this study confirms that hiPSCs can adopt LSEC-like features and provides insight into LSEC specification. This humanised xenograft system can be applied to further interrogate LSEC developmental biology and pathophysiology, bypassing current logistical obstacles associated with primary human LSECs. Impact and implications: Liver sinusoidal endothelial cells (LSECs) are important cells for liver biology, but better model systems are required to study them. We present a pluripotent stem cell xenografting model that produces human LSEC-like cells. A detailed and longitudinal transcriptomic analysis of the development of LSEC-like cells is included, which will guide future studies to interrogate LSEC biology and produce LSEC-like cells that could be used for regenerative medicine.

Early onset pancreatic cancer-exploring contemporary treatment and outcomes using real-world data.

BACKGROUND: Pancreatic cancer incidence is increasing in younger populations. Differences between early onset pancreatic cancer (EOPC) and later onset pancreatic cancer (LOPC), and how these should inform management warrant exploration in the contemporary setting. METHODS: A prospectively collected multi-site dataset on consecutive pancreatic adenocarcinoma patients was interrogated. Patient, tumour, treatment, and outcome data were extracted for EOPC (≤50 years old) vs LOPC (>50 years old). RESULTS: Of 1683 patients diagnosed between 2016 and 2022, 112 (6.7%) were EOPC. EOPC more frequently had the tail of pancreas tumours, earlier stage disease, surgical resection, and trended towards increased receipt of chemotherapy in the curative setting compared to LOPC. EOPC more frequently received 1st line chemotherapy, 2nd line chemotherapy, and chemoradiotherapy than LOPC in the palliative setting. Recurrence-free survival was improved for the tail of pancreas EOPC vs LOPC in the resected setting; overall survival was superior for EOPC compared to LOPC across the resected, locally advanced unresectable and metastatic settings. CONCLUSIONS: EOPC remains a small proportion of pancreatic cancer diagnoses. The more favourable outcomes in EOPC suggest these younger patients are overall deriving benefits from increased treatment in the curative setting and increased therapy in the palliative setting.

Mottle: Accurate pairwise substitution distance at high divergence through the exploitation of short-read mappers and gradient descent.

Current tools for estimating the substitution distance between two related sequences struggle to remain accurate at a high divergence. Difficulties at distant homologies, such as false seeding and over-alignment, create a high barrier for the development of a stable estimator. This is especially true for viral genomes, which carry a high rate of mutation, small size, and sparse taxonomy. Developing an accurate substitution distance measure would help to elucidate the relationship between highly divergent sequences, interrogate their evolutionary history, and better facilitate the discovery of new viral genomes. To tackle these problems, we propose an approach that uses short-read mappers to create whole-genome maps, and gradient descent to isolate the homologous fraction and calculate the final distance value. We implement this approach as Mottle. With the use of simulated and biological sequences, Mottle was able to remain stable to 0.66-0.96 substitutions per base pair and identify viral outgroup genomes with 95% accuracy at the family-order level. Our results indicate that Mottle performs as well as existing programs in identifying taxonomic relationships, with more accurate numerical estimation of genomic distance over greater divergences. By contrast, one limitation is a reduced numerical accuracy at low divergences, and on genomes where insertions and deletions are uncommon, when compared to alternative approaches. We propose that Mottle may therefore be of particular interest in the study of viruses, viral relationships, and notably for viral discovery platforms, helping in benchmarking of homology search tools and defining the limits of taxonomic classification methods. The code for Mottle is available at https://github.com/tphoward/Mottle_Repo.

Tomato Brown Rugose Fruit Virus: Survival and Disinfection Efficacy on Common Glasshouse Surfaces.

Tomato brown rugose fruit virus (ToBRFV) is a contact-transmitted tobamovirus affecting many tomato growing regions of the world. This study investigated the effects of different glasshouse surfaces on the survival of the virus; the efficacy of different disinfectants; and heat treatment against ToBRFV (surfaces included steel, aluminium, hard plastic, polythene, glass and concrete). A bioassay followed by ELISA was used to check virus viability. ToBRFV survived for at least 7 days on all surfaces tested and on some for at least 6 months. The virus survived for over two hours on hands and gloves. Hand washing was shown to be unreliable for the removal of the virus. Glutaraldehyde and quaternary ammonium compound disinfectants were effective at one hour on all surfaces. Some other disinfectants were effective at one hour of contact time, on all surfaces except concrete. Sodium hypochlorite was partially effective against ToBRFV, even on concrete. A 5 min soak of plastic trays in water at 90 °C was effective at denaturing ToBRFV; however, 5 min at 70 °C was not. Heating infected sap showed the thermal inactivation point to be 90 °C, confirming the hot water treatment results and showing that deactivation was due to the heat treatment and not a washing effect of the water.

Are the screening guidelines for branch duct intraductal papillary mucinous neoplasms cost-effective in an Australian setting?

BACKGROUNDS: Intraductal papillary mucinous neoplasms (IPMN) are cystic neoplasms of the pancreatic ductal system. These incidental cystic lesions are increasingly found on radiological imaging and screened for malignant transformation. The Fukuoka consensus guidelines recommend screening with computed tomography, magnetic resonance imaging or endoscopic ultrasound. Branch duct IPMN (BD-IPMN) have significantly lower malignancy and mortality rates compared to main duct IPMN. Our aim was to assess the cost-effectiveness of guideline's recommendations for BD-IPMN screening of cysts between 2 and 3 cm in an Australian context. METHODS: Markov model decision analysis was used to calculate the incremental cost-effectiveness ratio (ICER) of screening. The ICER was compared to a willingness to pay (WTP) threshold of $50 000. We performed scenario analysis to examine the effect of cyst size and non-linearity of malignancy rate on ICER. Probabilistic sensitivity analyses (PSA) were performed on our input parameters. RESULTS: Screening resulted in 586 quality adjusted life years gained and a net present value of $20 379 939, resulting in a base-case ICER of $34 758. After scenario analysis for non-linearity of malignancy rate the ICER increases to $64 555, which is above the WTP threshold. PSA indicates that ICER is most susceptible to the pre-test malignancy rate. CONCLUSION: This cost analysis demonstrates that screening of 2-3 cm BD-IPMN according to current guidelines is unlikely to be cost-effective in an Australian context. To determine the true ICER, a cost analysis on real-world data is required.

Managing the deluge of newly discovered plant viruses and viroids: an optimized scientific and regulatory framework for their characterization and risk analysis.

The advances in high-throughput sequencing (HTS) technologies and bioinformatic tools have provided new opportunities for virus and viroid discovery and diagnostics. Hence, new sequences of viral origin are being discovered and published at a previously unseen rate. Therefore, a collective effort was undertaken to write and propose a framework for prioritizing the biological characterization steps needed after discovering a new plant virus to evaluate its impact at different levels. Even though the proposed approach was widely used, a revision of these guidelines was prepared to consider virus discovery and characterization trends and integrate novel approaches and tools recently published or under development. This updated framework is more adapted to the current rate of virus discovery and provides an improved prioritization for filling knowledge and data gaps. It consists of four distinct steps adapted to include a multi-stakeholder feedback loop. Key improvements include better prioritization and organization of the various steps, earlier data sharing among researchers and involved stakeholders, public database screening, and exploitation of genomic information to predict biological properties.

Tomato brown rugose fruit virus in aqueous environments - survival and significance of water-mediated transmission.

Tomato brown rugose fruit virus (ToBRFV) has recently emerged as a major disease of tomatoes and peppers. ToBRFV is a seed- and contact-transmitted virus. In Slovenia, ToBRFV RNA was detected in samples of wastewater, river, and water used to irrigate plants. Even though the source of detected RNA could not be clearly established, this raised the question of the significance of the detection of ToBRFV in water samples and experimental studies were performed to address this question. The data presented here confirm that the release of virus particles from the roots of infected plants is a source of infectious ToBRFV particles in water and that the virus can remain infective up to four weeks in water stored at room temperature, while its RNA can be detected for much longer. These data also indicate that irrigation with ToBRFV-contaminated water can lead to plant infection. In addition, it has been shown that ToBRFV circulated in drain water in commercial tomato greenhouses from other European countries and that an outbreak of ToBRFV can be detected by regular monitoring of drain water. A simple method for concentrating ToBRFV from water samples and a comparison of the sensitivity of different methods, including the determination of the highest ToBRFV dilution still capable of infecting test plants, were also investigated. The results of our studies fill the knowledge gaps in the epidemiology and diagnosis of ToBRFV, by studying the role of water-mediated transmission, and provide a reliable risk assessment to identify critical points for monitoring and control.

Tomato Brown Rugose Fruit Virus Pandemic.

Tomato brown rugose fruit virus (ToBRFV) is an emerging tobamovirus. It was first reported in 2015 in Jordan in greenhouse tomatoes and now threatens tomato and pepper crops around the world. ToBRFV is a stable and highly infectious virus that is easily transmitted by mechanical means and via seeds, which enables it to spread locally and over long distances. The ability of ToBRFV to infect tomato plants harboring the commonly deployed Tm resistance genes, as well as pepper plants harboring the L resistance alleles under certain conditions, limits the ability to prevent damage from the virus. The fruit production and quality of ToBRFV-infected tomato and pepper plants can be drastically affected, thus significantly impacting their market value. Herein, we review the current information and discuss the latest areas of research on this virus, which include its discovery and distribution, epidemiology, detection, and prevention and control measures, that could help mitigate the ToBRFV disease pandemic.

International Trade and Local Effects of Viral and Bacterial Diseases in Ornamental Plants.

Since the 1950s, there have been major changes in the scope, value, and organization of the ornamental plant industry. With fewer individual producers and a strong trend toward consolidation and globalization, increasing quantities of diverse plant genera and species are being shipped internationally. Many more ornamentals are propagated vegetatively instead of by seed, further contributing to disease spread. These factors have led to global movement of pathogens to countries where they were not formerly known. The emergence of some previously undescribed pathogens has been facilitated by high-throughput sequencing, but biological studies are often lacking, so their roles in economic diseases are not yet known. Case studies of diseases in selected ornamentals discuss the factors involved in their spread, control measures to reduce their economic impact, and some potential effects on agronomic crops. Advances in diagnostic techniques are discussed, and parallels are drawn to the international movement of human diseases.

Genomic High Plains Wheat Mosaic Virus Sequences from Australia: Their Phylogenetics and Evidence for Emaravirus Recombination and Reassortment.

High Plains wheat mosaic virus (HPWMoV) causes a serious disease in major wheat-growing regions worldwide. We report here the complete or partial genomic sequences of five HPWMoV isolates from Australian wheat samples. Phylogenetic analysis of the nucleotide sequences of the eight genomic segments of these five isolates together with others from Genbank found all eight genes formed two lineages, L1 and L2. L1 contained a single isolate from Colorado in the North American Great Plains Region (GPR), and L2 had two unresolved clusters, A and B, of isolates from Australia and the GPR. A quarter of the L2B isolate sequences of the nucleocapsid gene (RNA3) were recombinant, which is unexpected as little evidence of recombination exists in viruses with negative single-stranded RNA genomes. Phylogenies calculated from the amino acid sequences of HPWMoV's RNA-dependent RNA-polymerase (RNA1), glycoprotein (RNA2), and nucleocapsid protein (RNA3) showed they were closest to those of Palo Verde broom virus. However, its movement protein (RNA4) was closer to those of Ti ringspot-associated and common oak ringspot-associated viruses, indicating the RNA4 segments of their ancestors reassorted to produce the current emaraviruses. To avoid increased yield losses from co-infection, biosecurity measures are advised to avoid HPWMoV introduction to countries where wheat streak mosaic virus already occurs.

Use and outcomes from neoadjuvant chemotherapy in borderline resectable pancreatic ductal adenocarcinoma in an Australasian population.

BACKGROUND: Use of neoadjuvant (NA) chemotherapy is recommended when pancreatic ductal adenocarcinoma (PDAC) is borderline resectable METHOD: A retrospective analysis of consecutive patients with localized PDAC between January 2016 and March 2019 within the Australasian Pancreatic Cancer Registry (PURPLE, Pancreatic cancer: Understanding Routine Practice and Lifting End results) was performed. Clinicopathological characteristics, treatment, and outcome were analyzed. Overall survival (OS) comparison was performed using log-rank model and Kaplan-Meier analysis. RESULTS: The PURPLE database included 754 cases with localised PDAC, including 148 (20%) cases with borderline resectable pancreatic cancer (BRPC). Of the 148 BRPC patients, 44 (30%) underwent immediate surgery, 80 (54%) received NA chemotherapy, and 24 (16%) were inoperable. The median age of NA therapy patients was 63 years and FOLFIRINOX (53%) was more often used as NA therapy than gemcitabine/nab-paclitaxel (31%). Patients who received FOLFIRINOX were younger than those who received gemcitabine/nab-paclitaxel (60 years vs. 67 years, p = .01). Surgery was performed in 54% (43 of 80) of BRPC patients receiving NA chemotherapy, with 53% (16 of 30) achieving R0 resections. BRPC patients undergoing surgery had a median OS of 30 months, and 38% (9 of 24) achieved R0 resection. NA chemotherapy patients had a median OS of 20 months, improving to 24 months versus 10 months for patients receiving FOLFIRINOX compared to gemcitabine/nab-paclitaxel (Hazard Ratio (HR) .3, p < .0001). CONCLUSIONS: NA chemotherapy use in BRPC is increasing in Australia. One half of patients receiving NA chemotherapy proceed to curative resection, with 53% achieving R0 resections. Patients receiving Infusional 5-flurouracil, Irinotecan and Oxaliplatin (FOLIRINOX) had increased survival than gemcitabine/nab-paclitaxel. Treatment strategies are being explored in the MASTERPLAN and DYNAMIC-Pancreas trials.

Enhanced Apiaceous Potyvirus Phylogeny, Novel Viruses, and New Country and Host Records from Sequencing Apiaceae Samples.

The family Apiaceae comprises approximately 3700 species of herbaceous plants, including important crops, aromatic herbs and field weeds. Here we report a study of 10 preserved historical or recent virus samples of apiaceous plants collected in the United Kingdom (UK) import interceptions from the Mediterranean region (Egypt, Israel and Cyprus) or during surveys of Australian apiaceous crops. Seven complete new genomic sequences and one partial sequence, of the apiaceous potyviruses apium virus Y (ApVY), carrot thin leaf virus (CaTLV), carrot virus Y (CarVY) and celery mosaic virus (CeMV) were obtained. When these 7 and 16 earlier complete non-recombinant apiaceous potyvirus sequences were subjected to phylogenetic analyses, they split into 2 separate lineages: 1 containing ApVY, CeMV, CarVY and panax virus Y and the other CaTLV, ashitabi mosaic virus and konjac virus Y. Preliminary dating analysis suggested the CarVY population first diverged from CeMV and ApVY in the 17th century and CeMV from ApVY in the 18th century. They also showed the "time to most recent common ancestor" of the sampled populations to be more recent: 1997 CE, 1983 CE and 1958 CE for CarVY, CeMV and ApVY, respectively. In addition, we found a new family record for beet western yellows virus in coriander from Cyprus; a new country record for carrot torradovirus-1 and a tentative novel member of genus Ophiovirus as a co-infection in a carrot sample from Australia; and a novel member of the genus Umbravirus recovered from a sample of herb parsley from Israel.

Systematic Comparison of Nanopore and Illumina Sequencing for the Detection of Plant Viruses and Viroids Using Total RNA Sequencing Approach.

High-throughput sequencing (HTS) has become an important tool for plant virus detection and discovery. Nanopore sequencing has been rapidly developing in the recent years and offers new possibilities for fast diagnostic applications of HTS. With this in mind, a study was completed, comparing the most established HTS platform (MiSeq benchtop sequencer-Illumina), with the MinION sequencer (Oxford Nanopore Technologies) for the detection of plant viruses and viroids. Method comparisons were performed on five selected samples, containing two viroids, which were sequenced using nanopore technology for the first time and 11 plant viruses with different genome organizations. For all samples, sequencing libraries for the MiSeq were prepared from ribosomal RNA-depleted total RNA (rRNA-depleted totRNA) and for MinION sequencing, direct RNA sequencing of totRNA was used. Moreover, for one of the samples, which contained five different plant viruses and a viroid, three additional variations of sample preparation for MinION sequencing were also used: direct RNA sequencing of rRNA-depleted totRNA, cDNA-PCR sequencing of totRNA, and cDNA-PCR sequencing of rRNA-depleted totRNA. Whilst direct RNA sequencing of total RNA was the quickest of the tested approaches, it was also the least sensitive: using this approach, we failed to detect only one virus that was present in a sample at an extremely low titer. All other MinION sequencing approaches showed improved performance with outcomes similar to Illumina sequencing, with cDNA-PCR sequencing of rRNA-depleted totRNA showing the best performance amongst tested nanopore MinION sequencing approaches. Moreover, when enough sequencing data were generated, high-quality consensus viral genome sequences could be reconstructed from MinION sequencing data, with high identity to the ones generated from Illumina data. The results of this study implicate that, when an appropriate sample and library preparation are selected, nanopore MinION sequencing could be used for the detection of plant viruses and viroids with similar performance as Illumina sequencing. Taken as a balance of practicality and performance, this suggests that MinION sequencing may be an ideal tool for fast and affordable virus diagnostics.

Phylogenetics and Evolution of Potato Virus V: Another Potyvirus that Originated in the Andes.

Potato virus V (PVV) causes a disease of potato (Solanum tubersosum) in South and Central America, Europe, and the Middle East. We report here the complete genomic sequences of 42 new PVV isolates from the potato's Andean domestication center in Peru and of eight historical or recent isolates from Europe. When the principal open reading frames of these genomic sequences together with those of nine previously published genomic sequences were analyzed, only two from Peru and one from Iran were found to be recombinant. The phylogeny of the 56 nonrecombinant open reading frame sequences showed that the PVV population had two major phylogroups, one of which formed three minor phylogroups (A1 to A3) of isolates, all of which are found only in the Andean region of South America (Peru and Colombia), and the other formed two minor phylogroups, a basal one of Andean isolates (A4) that is paraphyletic to a crown cluster containing all the isolates found outside South America (World). This suggests that PVV originated in the Andean region, with only one minor phylogroup spreading elsewhere in the world. In minor phylogroups A1 and A3, there were two subclades on long branches containing isolates from S. phureja evolving more rapidly than the others, and these interfered with dating calculations. Although no temporal signal was directly detected among the dated nonrecombinant sequences, PVV and potato virus Y (PVY) are from the same potyvirus lineage and are ecologically similar, so "subtree dating" was done via a single maximum likelihood phylogeny of PVV and PVY sequences, and PVY's well-supported 157 ce "time to most common recent ancestor" was extrapolated to date that of PVV as 29 bce. Thus the independent historical coincidences supporting the datings of the PVV and PVY phylogenies are the same; PVV arose ≥2,000 years ago in the Andes and was taken to Europe during the Columbian Exchange, where it diversified around 1853 ce, soon after the European potato late blight pandemic. PVV is likely to be more widespread than currently realized and is of biosecurity relevance for world regions that have not yet recorded its presence.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Development of simplex and multiplex RT-qPCR assays for the detection of three cryptic viruses of black-grass (Alopecurus myosuroides).

Simplex and multiplex RT-qPCR assays were developed for Alopecurus myosuroides partitivirus 1 (AMPV1), Alopecurus myosuroides partitivirus 2 (AMPV2) and Alopecurus myosuroides varicosavirus 1 (AMVV1), and compared to the existing conventional PCR assays. All assays had a high specificity and their sensitivity was increased compared to the conventional RT-PCR assays. As viral quantification is an important element in comparative experiments, the effect of high- and low-temperature drying treatments, prior to RNA extraction and analysis, was studied and optimised. AMVV1 detection was reduced by both drying treatments, but particularly by the high-temperature. AMPV1 and AMPV2 detection on the other hand was not impeded by the drying treatments, and enables standardisation of plant tissue prior to extraction, in particular for quantitative analysis.

A novel high-throughput sequencing approach reveals the presence of a new virus infecting Rosa: rosa ilarvirus-1 (RIV-1).

Roses are one of the most valuable ornamental flowering shrubs grown worldwide. Despite the widespread of rose viruses and their impact on cultivation, they have not been studied in detail in the United Kingdom (UK) since the 1980's. As part of a survey of rose viruses entering the UK, 35 samples were collected at Heathrow Airport (London, UK) and were tested by RT-qPCR for different common rose viruses. Of the 35 samples tested using RT-qPCR for prunus necrotic ringspot virus (PNRSV; genus Ilarvirus), 10 were positive. Confirmatory testing was performed using RT-PCR with both PNRSV-specific and ilarvirus-generic primers, and diverse results were obtained: One sample was exclusively positive when using the ilarvirus-generic primers, and subsequent sequencing of the RT-PCR product revealed homology to other ilarviruses but not PNRSV. Further work to characterise the virus was performed using high throughput sequencing, both the MinION Flongle and Illumina MiSeq. The sequencing confirmed the presence of a new virus within group 2 of the genus Ilarvirus and we propose the name "rosa ilarvirus-1″ (RIV-1). Here, we describe the identification of a novel virus using the low-cost Flongle flow cell and discuss its potential as a front-line diagnostic tool.

Integrating High throughput Sequencing into Survey Design Reveals Turnip Yellows Virus and Soybean Dwarf Virus in Pea (Pisum Sativum) in the United Kingdom.

There is only limited knowledge of the presence and incidence of viruses in peas within the United Kingdom, therefore high-throughput sequencing (HTS) in combination with a bulk sampling strategy and targeted testing was used to determine the virome in cultivated pea crops. Bulks of 120 leaves collected from twenty fields from around the UK were initially tested by HTS, and presence and incidence of virus was then determined using specific real-time reverse-transcription PCR assays by testing smaller mixed-bulk size samples. This study presents the first finding of turnip yellows virus (TuYV) in peas in the UK and the first finding of soybean dwarf virus (SbDV) in the UK. While TuYV was not previously known to be present in UK peas, it was found in 13 of the 20 sites tested and was present at incidences up to 100%. Pea enation mosaic virus-1, pea enation mosaic virus-2, pea seed-borne mosaic virus, bean yellow mosaic virus, pea enation mosaic virus satellite RNA and turnip yellows virus associated RNA were also identified by HTS. Additionally, a subset of bulked samples were re-sequenced at greater depth to ascertain whether the relatively low depth of sequencing had missed any infections. In each case the same viruses were identified as had been identified using the lower sequencing depth. Sequencing of an isolate of pea seed-borne mosaic virus from 2007 also revealed the presence of TuYV and SbDV, showing that both viruses have been present in the UK for at least a decade, and represents the earliest whole genome of SbDV from Europe. This study demonstrates the potential of HTS to be used as a surveillance tool, or for crop-specific field survey, using a bulk sampling strategy combined with HTS and targeted diagnostics to indicate both presence and incidence of viruses in a crop.

Complete genome sequence of a new isolate of caper latent virus in caper.

The genome of a new carlavirus isolate from asymptomatic wild Capparis spinosa L. plants in Sicily was sequenced via high-throughput sequencing (HTS) and 5'/3' RACE experiments. The complete genomic sequence was found to be 8,280 nt in length, excluding the poly(A) tail, and contained five putative open reading frames (ORFs). Molecular characterization revealed a close relationship to caper latent virus (CapLV), with 87% and 90% nucleotide sequence identity to available partial sequences of the ORFs encoding the replicase and coat protein of that virus. According to the molecular criteria for species demarcation, which is based on the ORF-1- and ORF-5-encoded proteins, the virus characterized in this study could be considered a variant of CapLV, and we have thus designated it as CapLV-W.

Metal stents are safe and cost-effective for preoperative biliary drainage in resectable pancreaticobiliary tumours.

BACKGROUNDS: To compare the complication rates and overall costs of self-expandable metal stents (SEMS) and plastic stents (PS) in clinically indicated preoperative biliary drainage (PBD) prior to a pancreatoduodenectomy (PD). METHODS: We conducted an Australian multicentre retrospective cohort study using the databases of four tertiary hospitals. Adult patients who underwent clinically indicated endoscopic PBD prior to PD from 2010 to 2019 were included. Rates of complications attributable to PBD, surgical complications and pre-operative endoscopic re-intervention were calculated. Costing data were retrieved from our Financial department. RESULTS: Among the 157 included patients (mean age 66.6 ± 9.8 years, 45.2% male), 49 (31.2%) received SEMS and 108 received PS (68.8%). Baseline bilirubin was 187.5 ± 122.6 µmol/L. Resection histopathology showed mainly adenocarcinoma (93.0%). Overall SEMS was associated less complications (12.2% vs. 28.7%, p = 0.02) and a lower pre-operative endoscopic re-intervention rate (4.3 vs. 20.8%, p = 0.03) compared with PS. There was no difference in post-PD complication rates. On multivariate logistic regression analysis, stent type was an independent risk factor of PBD complication (OR of SEMS compared to PS 0.24, 95% CI 0.07-0.79, p = 0.02) but not for any secondary outcome measures. Upfront material costs were $56USD for PS and $1991USD for SEMS. Accounting for rates of complications, average costs were similar ($3110USD for PS and $3026USD for SEMS). CONCLUSION: In resectable pancreaticobiliary tumours, SEMS for PBD was associated with reduced risk of overall PBD-related complications and pre-surgical endoscopic reintervention rates and was comparable to PS in terms of overall cost.